Camera system, video selection apparatus and video selection method

ABSTRACT

A camera system includes a plurality of camera apparatuses that output respective video data in a packetized format. A relaying apparatus receives the packetized video data from the plurality of camera apparatuses and relays selected selected packetized video data from a particular one of the plurality of camera apparatuses on a frame basis.

This is a continuation of application Ser. No. 14/259,427, filed Apr.23, 2014, which is a continuation of application Ser. No. 13/154,003,filed Jun. 6, 2011, which is entitled to the priority filing date ofJapanese application 2010-134111, filed Jun. 11, 2010, the entirety ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a camera system, a video selectionapparatus, and a video selection method.

2. Description of the Related Art

In a camera system used in a broadcasting station and the like, a camerahead unit (CHU) for outputting a video signal and a camera control unit(CCU) for receiving the video signal are connected to each other througha triaxial cable or an optical fiber cable (Japanese Patent ApplicationLaid-Open Nos. 2005-057499 and 2005-064816).

SUMMARY OF THE DISCLOSURE

However, when the CHU is connected to the CCU through a triaxial cableor an optical fiber cable in a one-to-one manner, a video signalphotographed by the CHU needs to be extracted from the CCU. Furthermore,a GEN-LOCK signal, a control signal, a return video signal and the likefor the CHU need to be input from the CCU.

As a result, in a camera system used in a broadcasting station and thelike, since a plurality of cables are connected to the CCU, time andeffort are necessary for the connections thereof and the installation ofthe cables.

Furthermore, when the CHU and the like are added, exchanged orrearranged after one camera system is constructed built, much time andeffort are necessary, for example, for changing the cable connection ofthe CCU.

In the camera system as described above, it is necessary to facilitatesystem modification and the like by reducing the number of cableconnections to the CCU.

In this regard, a system having CCUs that are same in number as aplurality of cameras may be considered. However, in such a case, sinceall of N CCUs should have a decoding function, it is not possible toavoid an increase in the system cost. Furthermore, it is necessary toconnect the CCUs to a video live switcher by wires corresponding to thenumber of the cameras. However, in a video source actually used inbroadcasting, for example, when a video live switcher mixes two screenswith each other, since it is sufficient for two input sources to beinput, cable inputs corresponding to all the cameras are not necessary.Therefore, even in the system having CCUs that are same in number as aplurality of cameras, redundant parts may exist during systemconfiguration.

In light of the foregoing, it is desirable to provide a novel andmodified camera system, video selection apparatus, and video selectionmethod, which can select a desired video from videos from a plurality ofcamera apparatuses and thus simplify system configuration.

One implementation of the camera system includes a plurality of cameraapparatuses to output respective video signals in the form of packetizedvideo data. A relay apparatus is coupled to the plurality of cameraapparatuses to relay selected packetized video data received from theplurality of camera apparatuses. The relay apparatus includes areceiving unit to receive the packetized video data from the pluralityof camera apparatuses and a control unit to determine selectedpacketized video data from a particular one of the plurality of cameraapparatuses based on an input control signal. A switch unit, selects andoutputs the selected packetized video data on a frame basis.

According to the embodiments of the present disclosure described above,it is possible to select a desired video from videos from a plurality ofcamera apparatuses and simplify system configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a camera system accordingto each embodiment of the present disclosure.

FIG. 2 is a schematic diagram showing a configuration of a systemaccording to a first embodiment.

FIG. 3 is a detailed block diagram showing the configuration of thefirst embodiment.

FIG. 4 is a schematic diagram showing a configuration of a header in anRIP format, which is used when transmitting data obtained by encoding avideo.

FIG. 5 is a schematic diagram showing parameter information of the RTPformat shown in FIG. 4.

FIG. 6 is a flowchart showing a process flow of switch control in whichan IP switch section performs video switching.

FIG. 7 is a schematic diagram for explaining signal switching in thecontrol, of FIG. 6.

FIG. 8 is a schematic diagram showing a case where a decoding process isperformed by the video frame.

FIG. 9 is a schematic diagram showing a configuration of a systemaccording to a second embodiment.

FIG. 10 is a schematic diagram showing a configuration of a relayapparatus according to the second embodiment.

FIG. 11 is a schematic diagram showing a configuration of a relayapparatus according to a third embodiment.

FIG. 12 is a schematic diagram showing the detailed configuration of therelay apparatus according to the third embodiment.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

Further, the description will be made in the following order:

1. First embodiment

(1) Basic technology

(2) System configuration example

(3) Procedure of switch control

2. Second embodiment

(1) System configuration example

3. Third embodiment

(1) System configuration example

1. First Embodiment (1) Outline

In a camera control system according to the present embodiment, a cameravideo signal is packetized into an IP packet and transmitted using acable such as Ethernet (registered trademark) through an IP network, anda camera control unit (CCU) receiving unit receives and decodes the IPpacket to output a video signal. According to the present embodiment,the system has a function obtained by integrating an IP switchingfunction of selecting a desired video from videos of a plurality ofcameras with a selection/control/effect function of a camera video. Inthe conventional system, CCUs that are the same in number as a pluralityof cameras is necessary and the number of wirings between the CCUs and avideo switcher is large. In the system according to the presentembodiment, only the maximum number of CCUs necessary for the output ofa video switcher are provided. Furthermore, by integrating acontrol/selection function and further an effect function into an IPswitch, a function equivalent to that of a video live switcher providedto the rear stage of the CCU can be achieved using a general purposeswitch device and an Ethernet (registered trademark) interface.Furthermore, simplification of wiring using an IP, system modificationincluding expansion and the like, and integration with other IP devicesare facilitated.

FIG. 1 is a schematic configuration diagram of a camera system 100according to each embodiment of the present disclosure. The camerasystem 100 shown in FIG. 1, for example, is used in a broadcastingstation and the like and includes camera head units (CI-IUs) 200 andCCUs 300. The CHUs 200 and the CCUs 300 are connected to a relayapparatus 500 using twisted pair cables 400. The twisted pair cable 400may be a cable conforming to the Institute of Electrical and ElectronicsEngineers (IEEE) 802.3 and the like.

The IEEE, 802.3 is the standard for a data communication system using apacket, and packetizes communication data into a packet by apredetermined data amount and performs communication using the packet.Thus, in the camera system 100 shown in FIG. 1, the CHUs 200 and theCCUs 300 packetize a video signal, an audio signal, a control signal, aGEN-LOCK signal and the like into a packet and transmit the packetthrough an asynchronous transmission line. Then, in the camera system100 shown in FIG. 1, the video signal which includes a photographed mainline video signal, the audio signal, the control signal, the GEN-LOCKsignal and the like may be extracted from the relay apparatus 500 in themiddle of the CHUs 200 and the CCUs 300, or may be inserted thereto.

Furthermore, the relay apparatus 500 outputs the video signals, whichhave been transmitted from the CHUs 200, and return video signals, whichhave been transmitted from the CCUs 300, to the outside. These videosignals, for example, can be recognized by monitor apparatuses connectedto the CHUs 200, a monitor apparatus (not shown in FIG. 1) connected tothe relay apparatus 500, and the like. As described above, in the camerasystem 100 shown in FIG. 1, a video relay system using the CHUs 200 canbe simply configured, installed and operated at a low cost.

The relay apparatus 500 includes the configuration of a switching hubprovided with a plurality of ports. The switching hub selects ports ofoutput destinations based on destinations of packets input from eachport and outputs the packets from the selected ports, respectively.Furthermore, when a broadcast address is used in a packet, it ispossible for the switching hub to basically output a received packetfrom all ports.

In the conventional camera system, it is necessary to provide N CCUs 300that are the same in number as a plurality of (N) cameras 200 and alloutputs of the CCUs 300 are input to the video live switcher of a rearstage. Specifically, in a hi-vision (HD) video, a video codec mainlyperforms an encoding process due to band limitation and all of the NCCUs 300 should have a decoding function, resulting in an increase in,the system cost.

Furthermore, in the conventional camera system as described above, it isnecessary to connect the CCUs 300 to the video live switcher using NHD-SDI cables. However, in a video source actually used in broadcasting,for example, when the video live switcher mixes two screens with eachother, since it is sufficient for two input sources to be input, Ninputs are not necessary. Even for an effect process using, amulti-source by a complicated switcher, it is sufficient for about fourscreens to be treated and redundant parts exist in the conventionalsystem configuration. In this regard, when a minimum configuration istaken into consideration, for example, when a video is selected from aplurality of CCUs and broadcast using only switching without an effect,it is sufficient to have only one CCU.

Thus, if there are functions corresponding to the video live switcher orthe CCUs 300 with the number for the effect process, it is not necessaryto provide N CCUs 300 with respect to N video sources. Furthermore,selection of a source from a camera using a live video switcher andselection of a packet using an IP switch have the same function in termsof source selection.

For this reason, the present embodiment integrally controls thefunctions and bodies of the live video switcher and the IP switch,thereby constructing a system with a simple configuration. In detail, inthe present embodiment, a process is performed in units of video frameas with the live video switcher, a function equivalent to that of anapparatus for performing a process within less than a video frame timeis integrally controlled using, the IP switch, and a video frame isdetected to switch an IP packet Since such control is perforated basedon a general purpose IP switch, it is possible to flexibly construct asystem at a low cost.

In the present embodiment, a function equivalent to that of the livevideo switcher used in a broadcasting station and the like may beperformed for data such as an IP-packetized and transmitted video. Thatis, in response to the input of a video switching signal of the livevideo switcher, a video signal is output from the head of the next framein a switcher. Thus, when a signal is encoded and compressed in IPpacketization, a codec with no frame delay, for example, a line-basedcodec of JPEG 2000, a line-based codec with low delay, or a codec inunits of slice is performed. Furthermore, a codec for performing a lowdelay process in units of macro block of MPEG 2 or H.264/AVC is used Byusing the codec, encoding and decoding processes of one frame or lessare possible.

(2) System Configuration Example

Hereinafter, the first embodiment will be described. FIG. 2 is aschematic diagram showing a configuration of a system according to thefirst embodiment. The present embodiment shows a basic configuration ofeach embodiment to be described below. As shown in FIG. 2, the presentsystem includes a plurality of cameras (CHUs) 200 (1 to N), a CCU 300, arelay apparatus 500, and a switching/selection control unit 600. Eachcamera 200 is connected to the relay apparatus 500 through anasynchronous transmission network, and the relay apparatus 500 isconnected to the CCU 300 through the asynchronous transmission network.The Ethernet (registered trademark) may be exemplified as theasynchronous transmission network. However, the present disclosure isnot limited thereto.

Each camera 200 converts a video into an IP packet and outputs the IPpacket. Video data may be non-compressed data or encoded data, and ispacketized into an IP packet conforming to an Internet protocol.Furthermore, the camera 200 may packetize a reversibly compressed videosignal according to a video encoding method. The IP switch/videoswitcher 500 includes an IP switch section 504 and a switch controlsection 506, and selects an IP packet, which is to be input to the CCU300 of the rear stage, from the cameras 1 to N (200), and outputs the IPpacket according to an instruction from the switching/selection controlunit 600. The output IP packet is rearranged by the CCU 300 andconverted into an HD-SDI signal to be output.

The switching/selection control unit 600 shown in FIG. 2 corresponds toa control panel of the video live switcher and receives an instructionfor selecting or switching a camera video which is output as a video ofbroadcasting and the like.

FIG. 3 is a detailed block diagram showing the configuration of thefirst embodiment, and shows a detailed configuration of the relayapparatus 500. As shown in FIG. 3, the relay apparatus 500 includes ananalyzing section 502 for analyzing an IP address and RTP information,an IP switch section 504, a switch control section 506, and a controlsignal receiving/analyzing/instructing section 508.

The control signal receiving/analyzing/instructing section 508 receivesa signal from the switching/selection control unit 600, analyzesreceived data, and outputs an instruction for switching/selecting thecamera 200 to the analyzing section 502. The analyzing section 502determines the transmission destination of input data from the camera200 based on an IP header and the like of the input data, and analyzeswhether the input data corresponds to the switching/selectinginstruction. The analyzing section 502 outputs an analysis result to theswitch control section 506. The switch control section 506 converts theinput analysis result into a control signal for controlling the IPswitch section 504 and outputs the control signal to the IP switchsection 504. Furthermore, IP packet data from each camera 200 istransmitted from the analyzing section 502 to the IP switch section 504.The IP switch section 504 switches or selects an input, packet based ona new destination registered in a switching table according to thecontrol signal which is input from the switch control section 506.

The IP switch section 504 has a plurality of ports and video signalscorresponding to each CHU 200, which are input from the analyzingsection 502, are input to the ports. Furthermore, one port is connectedto an output line of the CCU 300. If IP packets are input to the ports,to which the video signals corresponding to each CHU 200 are input, theIP switch section 504 connects a port of a transmission destination,which coincides with a destination registered in the switching table asa new destination, to a port connected to the output line of the CCU300. In this way, the IP switch section 504 can transmit one video ofthe plurality of CHUs 200 to the CCU 300 based on the destinationregistered in the switching table. Furthermore, the IP switch section504 selects a video signal by considering a delay amount until a videosignal is actually switched after the signal is received from theswitching/selection control unit 600, and smoothly performs videoswitching in units of frame.

As described above, when an IP packet of a live video is transmittedfrom each camera 200 to the relay apparatus 500, each camera 200, whichincludes an encoder, encodes video data using the encoder, packetizesresultant data and transmits a packet to the relay apparatus 500.

The switching/selection control unit 600 receives operation input forinstructing the selection of a desired video of the camera 200 from auser, and transmits a control signal for selecting the video to therelay apparatus 500. The control signal receiving/analyzing/instructingsection 508 analyzes the control signal and outputs an instruction tothe analyzing section 502 to switch and select the camera 200.

If the analysis result of the control signal is received, the analyzingsection 502 detects an IP address of the camera 200 desired by the user,which is included in the analysis result, and outputs the IP address tothe switch control section 506. The switch control section 506 convertsthe received signal to a control signal for controlling the IP switchsection 504 and outputs the control signal to the IP switch section 504.The IP switch section 504 switches and selects an input packet based onthe IP address desired by the user and outputs an IP packet of the videodesired by the user to the CCU 300 according to the control signal.

Furthermore, when video transmission is performed using the asynchronoustransmission network, a difference occurs in the transmission pathsaccording to the combinations of the CHUs 200 and the relay apparatus500, resulting in a difference in a delay amount. For this reason, therelay apparatus 500 transmits a reference signal from a synchronizationsignal generator 520 to the CHUs 200, and the CHUs 200 transmit a videosignal synchronized with the reference signal to the relay apparatus500. In addition, the synchronization signal generator 520 may beprovided separately from the relay apparatus 500. Meanwhile, althoughthe video signal is allowed to be synchronized with the referencesignal, since a difference occurs in the transmission paths according tothe combinations of the CHUs 200 and the relay apparatus 500, it isassumed that a difference occurs in delay amounts of the CHUs 200. Forthis reason, delay amounts between the CHUs 200 and the relay apparatus500 are acquired by the analyzing section 502. The analyzing section 502adjusts the delay amounts to decide an optimal delay amount. The decideddelay amount is notified to the CHUs 200, and the CHUs 200 appropriatelyset video buffers to adjust the timing of a video signal to arrive atthe relay apparatus 500. As a specific method for deciding a delayamount, there is a method of adjusting the video buffer to allow a delayamount of a CHU 200 with the largest delay to be equal to delay amountsof other CHUs 200. In addition, the setting of the video buffer may beperformed by the relay apparatus 500. By allowing the delay amounts tobe equal to each other, distortion of a video in video switching can bereliably prevented.

If the IP packet is received from the IP switch section 504 of the relayapparatus 500, the CCU 300 decodes the IP packet and outputs a decodedpacket as an HD-SDI video signal and the like.

When switching the videos of the cameras 200, the IP switch section 504identifies a video frame, and switches an IP packet including head dataconstituting the video frame. Hereinafter, a method for identifying avideo frame will be described.

FIG. 4 is a schematic diagram showing a configuration of a header in areal-time transfer protocol (RTP) format, which is used whentransmitting data obtained by encoding a video. Information on theheader is commonly defined regardless of an encoding scheme to bestored. FIG. 5 is a schematic diagram showing parameter information ofthe RIP format shown in FIG. 4. In order to identify a video frame, amarker bit, which is abbreviated as “M” in FIG. 5, is used. Usually, asthe marker bit of “M” shown in FIG. 5, “1” is established in a packetincluding final data of a video frame. Thus, when the marker bit “M”detected by the IP switch section 504 has a value of “0,” a packet fromthe same IP address is the head of the next video frame. Furthermore,when the “M” has a value of “1,” it is possible to identify that thepacket from the same IP address ends.

(3) Procedure of Switch Control

FIG. 6 is a flowchart showing a process flow of switch control in whichthe IP switch section 504 performs video switching. First, in step S10,a switching/selection signal corresponding to user's input is receivedfrom the switching/selection control unit 600. After theswitching/selection signal is received, in step S12, a new destination(an IP address) is registered in a switching table of the IP switchsection 504. However, until switch-based switching control is actuallyperformed (until step S20 is reached), an IP packet is not switched tothe new destination. In step S14, an RTP header is analyzed, and an RTPpacket header in a payload of the IP packet having an IP addresscorresponding to the user's input is analyzed.

In step S16, it is determined whether a marker bit “M” of the RTP packetheader has a value of “1.” If the marker bit “M” has a value of “1,”step S18 is performed so that the analyzed IP packet is output to thecurrent destination. Then, step S20 is performed so that switch-basedswitching control is performed and the switching table is changed basedon the new destination. In this way, the next IP packet is switched to apacket with the new destination. Meanwhile, if the marker bit “M” doesnot have a value of “1” in step S16, step S22 is performed so thatanalysis of an RTP header is performed with respect to the next IPpacket in the same manner as in step S14. By the above-describedcontrol, it is possible to perform switching from the head of the nextvideo frame.

FIG. 7 is a schematic diagram for explaining signal switching in thecontrol of FIG. 6. It is assumed that there are video frames #1, #2 and#3 and each video frame is packetized into an IP packet and input to therelay apparatus 500.

FIG. 7 is explained based on the N number of CHUs and N number of CCUssystem. A switching table represents N inputs from CHUs andcorresponding N outputs to CCUs, as shown in Table 1 below. FIG. 7 showsexample of switching the destination port by changing the destinationaddress, but embodiments are not limited to this example. The sourceaddress in the switching table can be changed so that the source portcould be switched, as shown in Table 1 and 3 below. Also the destinationaddress in the switching table can be changed so that the source portcould be switched, as shown in Table 1 and 2 below. (In this latterembodiment, the destination addresses of CAW, and CAM2 signals can bechanged so that the source ports of CAM1 and CAM2 could be switched,because this table just indicates relationship between input and output.Thus, changing the destination address in the table is equivalent tochanging the corresponding source address, which means switching thesource port). These two additional embodiments are applicable for thesystem having N number of CHUs and one CCU, as shown in FIG. 2 and Table4 below.

TABLE 1 Example switching table Source port Source DestinationDestination (CHU) address address port (CCU) CAM1 Xxx Aaa CCU-A CAM2 YyyBbb CCU-B CAM3 Zzz Ccc CCU-C

TABLE 2 Switching destination address Source port Source DestinationDestination (CHU) address address port (CCU) CAM1 Xxx Bbb CCU-B CAM2 YyyAaa CCU-A CAM3 Zzz Ccc CCU-C

TABLE 3 Switching source address Source port Source DestinationDestination (CHU) address address port (CCU) CAM2 Yyy Aaa CCU-A CAM1 XxxBbb CCU-B CAM3 Zzz Ccc CCU-C

TABLE 4 Example switching table assuming N number of CHU and one CCUsystem Source port Source Destination Destination (CHU) address addressport (CCU) CAM1 Xxx Aaa CCU-A CAM2 Yyy — — CAM3 Zzz — —

As described above, if the switching/selection signal is received instep S10, the new destination is registered in the switching table ofthe IP switch section 504. As shown in FIG. 7, the change to the newdestination is performed (step S20) after the marker bit “M” isdetected, and a routing table of a switch is switched. At the time atwhich the table is switched, the IP packet is output to the newdestination port. By such control, it is possible to perform a switchingprocess in units of video frame, which is equivalent to that of theconventional live video switcher, using the function of the IP switch.

Meanwhile, FIG. 8 shows a case where a decoding process is performed inunits of video frame. When the decoding process is performed in units ofvideo frame, since the decoding process is performed after all pieces ofdata of frame 1 of a video are buffered, a predetermined time isnecessary until data of the frame 1 is received to the end after acontrol signal for switching a video is, received, and the data of theframe 1 is further decoded and buffered. For this reason, as shown inFIG. 8, when the switching/selection signal has been received in themiddle of the video frame #1, after passing the predetermined timenecessary for receiving data of the video frame #1 to the end andfurther decoding the data, the frame #1 can be displayed at the timingof the next frame sync for the first time. Meanwhile, in FIG. 7, afterchanging the destination, it is possible to display a video after theswitching from the video frame #2. For this reason, in the case of FIG.8, a significant delay may occur in the switching of a video as comparedwith the case of FIG. 7. In the present embodiment, since encoding anddecoding processes are performed in units of blocks of a plurality oflines as shown in FIG. 4, after a control signal for switching a videois received, it is possible to directly switch a video from the nextframe.

Furthermore, in the system of the present embodiment, theswitching/selection control unit 600 may be configured to decide a videochannel to be switched/selected using the relay apparatus 500 (the IPswitch) in consideration of the maximum number of videos necessary forsynchronous output. In this way, it is possible to control a video byperforming a decoding process using only a necessary CCU 300.

In addition, in the present embodiment, the selection of a video framehas been exemplified. However, audio data may be selected. For example,in the case of a system which reproduces audio synchronized in units offrame of a video frame, the relay apparatus 500 can detect a packetincluding the head of an audio frame similarly to a video, and switch anIP packet by the delimiter of the audio frame.

According to the first embodiment as described above, if there arefunctions corresponding to a video live switcher or CCUs with the numbernecessary for an effect process, it is not necessary to provide N CCUswith respect to the sources of N cameras. Furthermore, since a functionof selecting a source from a camera by a live video switcher isequivalent to a function of selecting a packet by an IP switch in termsof source selection, the functions and the bodies of the live videoswitcher and the IP switch are integrally controlled, therebyconstructing a system with a simple configuration. Consequently,according to the present embodiment, a video frame is detected to switchan IP packet, so that it is possible to integrally control a function,which is equivalent to that of an apparatus for performing a process inunits of video frame and within less than a video frame time as with thelive video switcher, using the IP switch. Since such control isperformed based on a general purpose IP switch, it is possible toflexibly construct a system at a low cost.

For example, a minimum number of sources may be input as the input of avideo live switcher, and the number of the CCUs 300 can be reduced,thereby achieving a system with a simple configuration in which thenumber of wirings is small. Consequently, the relay apparatus 500 isallowed to have a switching function, so that a simple configuration canbe achieved, differently from the conventional camera system in which itis necessary to provide N CCUs that are the same in number as aplurality of N cameras and all outputs of the CCUs are input to a videolive switcher of a rear stage.

Furthermore, it is possible to switch a packet, which is transmittedusing an Ethernet (registered trademark) cable, using a general purposeswitch, thereby constructing a system with a low cost and high affinitywith a PC and the like, in which system modification including expansionand the like and, integration with other IP devices are facilitated. Forexample, a synchronization signal, a control command, sound, income, atary video, a return video and the like to a camera are multiplexed tothe same cable through an IP packet, so that a simple configuration canbe achieved.

2. Second Embodiment (1) System Configuration Example

Next, the second embodiment of the present disclosure will be described.FIG. 9 is a schematic diagram showing a configuration of a system,according to the second embodiment. The second embodiment may be appliedto a case where a visual effect such as fade-in or fade-out occurs whenswitching a video. In the first embodiment, the CCU 300 performs aprocess at the rear stage of the relay apparatus 500. However, thesecond embodiment uses a system obtained by integrating the CCU 300 intothe relay apparatus 500 (an IP switch/switcher). Thus, as the output ofthe relay apparatus 500, an HD-SDI video and the like are output.

FIG. 10 is a schematic diagram showing a configuration of the relayapparatus 500 according to the second embodiment. As shown in FIG. 10,the configuration of the second embodiment further includes CCUs 302 and304, a video switcher effect section 510, and an encoding/IP packetizingsection 512, in addition to the configuration of the relay apparatus 500according to the first embodiment. Furthermore, the second embodimentincludes a switching/selection/effect control unit 602, instead of theswitching/selection control unit 600 according to the first embodiment.

Switch control by the IP switch section 504 is performed in the samemanner as in the first embodiment. In the second embodiment, videosignals with two destinations before and after video switching are inputto the CCU 302 and the CCU 304, respectively. Then, output data decodedby the CCU 302 and the CCU 304 is subjected to an effect process in thevideo switcher effect section 510.

The video switcher effect section 510 has an effect function such aswiping/mixing and performs a process based on instructions from theswitching/selection/effect control unit 602. When a user desires aneffect in video switching, the user inputs the desire to theswitching/selection/effect control unit 602. For example, whenperforming wiping/mixing with respect to a video A output from the CCU302 and a video B output from the CCU 304, the video switcher effectsection 510 performs a process of synthesizing the video A with thevideo B based on the input of the user, which is input to theswitching/selection/effect control unit 602. Since the processed videois output to a monitor provided to the cameras 200 (1 to N) as a returnsignal, the video is subjected to an encoding process and an IPpacketizing process in the encoding/IP packetizing section 512 and inputto the IP switch section 504. The processed video is returned from theIP switch section 504 to the CHUs 200 (1 to N) through the analyzingsection 502, and displayed on monitors provided to each CHU 200.

As described above, in the present embodiment, the return signal isoutput to the CHUs 200 (1 to N) via the IP switch section 504, so that afunction equivalent to that of the multi-CCU can be performed through IPtransmission. In this way, operators of the CHUs 200 (1 to N) can viewvideos currently selected on the monitors provided to the cameras 200and effects when the videos are switched.

According to the second embodiment as described above, the relayapparatus 500 is allowed to have an effect processing function, so thatit is possible to simultaneously perform a switching process and aneffect process with respect to a video.

3. Third Embodiment (1) System Configuration Example

Next, the third embodiment of, the present disclosure will be described.FIG. 11 is a schematic diagram showing the configuration of the relayapparatus 500 according to the third embodiment. In the configurationshown in FIG. 11, a monitor 700 is connected to the relay apparatus 500,differently from the configuration shown in FIG. 9. In the thirdembodiment, a screen synthesis function is farther provided differentlyfrom the configuration according to the second embodiment, and videos ofthe CHUs 200 (1 to N) can be monitored by one monitor 700.

FIG. 12 is a schematic diagram showing the detailed configuration of therelay apparatus 500 according to the third embodiment. As shown in FIG.12, the third embodiment further includes a CCU 514 for processing allcamera videos and an image synthesizing section 516 for synthesizingimages, in addition to the configuration according to the secondembodiment shown in FIG. 10. Hereinafter, the CCU 514 is called a B typeand the CCUs 302 and 304 connected to the IP switch section 504 arecalled an A type. The B-type CCU 514 has a function of decoding videodata and may have a function equivalent to those of the A-type CCUs 302and 304. Furthermore, since the B-type CCU 514 displays a synthesizedimage on the monitor 700, it may have a function (quality) forsynthesizing a plurality of images, for example, may process a videowith a low resolution or a video with a low frame rate. Alternatively,instead of the B-type CCU 514, a CPU may be provided to decode a videoand output a decoded video to the image synthesizing section 516.

The CCU 514 decodes video data which is output from the IP switchsection 504 and corresponds to all CHUs 200 (1 to N) and outputs decodeddata to the image synthesizing section 516. The image synthesizingsection 516 synthesizes the decoded data, which corresponds to all theCHUs 200 (1 to N), into one screen and output synthesized data to theexternal monitor 700. In this way, a user can view videos of all CHUs200 (1 to N) with reference to the monitor 700. Then, the user selects adesired video from the videos displayed on the monitor 700 and allowsthe selected video to be input from the switching/selection/effectcontrol unit 602, so that the desired video can be output from the videoswitcher effect section 510.

According to the third embodiment as described above, the CHU 200 isconnected to the relay apparatus 500 having a video synthesis functionfor monitor display through an Ethernet (registered trademark) and thelike for inexpensive IP transmission, thereby achieving a video switcherwith a video frame level and a simple system capable of performing aneffect function, which have not been achieved in the conventional IPswitch.

While the preferred embodiments of the present invention have beendescribed above with reference to the accompanying drawings, the presentinvention is not limited to the above examples. A person skilled in theart may find various alternations and modifications within the scope ofthe appended claims, and it should be understood that they willnaturally come under the technical scope of the present invention.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2010-134111 filedin the Japan Patent Office on Jun. 11, 2010, the entire content of whichis hereby incorporated by reference.

What is claimed is:
 1. A relay apparatus for selecting packetized videodata provided from a plurality of camera apparatuses, comprising: areceiving unit to receive the packetized video data from the pluralityof camera apparatuses; an analyzing unit to determine if selectedpacketized video data from a particular one of the plurality of cameraapparatuses is to be switched to a selected destination address based ona control signal, the control signal provided for selecting desiredvideo data and for selecting the destination address; and a switch unitto select and output the selected packetized video data to a destinationcorresponding to the selected destination address on a frame basis, suchthat if the selected destination address is changed when a receivedpacket of video data is not a predetermined packet in a frame, theswitch unit does not output the packetized video data to a changeddestination until the predetermined packet is received.
 2. The relayapparatus of claim 1, wherein the packetized video data includes a headpacket, and wherein the switch unit selects and outputs starting from ahead packet of a next frame of the selected packetized video data. 3.The relay apparatus of claim 2, wherein each packet of video dataincludes a marker bit that identifies a final packet of a video frame.4. The relay apparatus of claim 3, wherein the switch unit determinesthe head packet of the next frame of the selected packetized video databased on the marker bit.
 5. A method for selecting packetized video dataprovided from a plurality of camera apparatuses, comprising: receivingthe packetized video data from the plurality of camera apparatuses;determining if selected packetized video data from a particular one ofthe plurality of camera apparatuses is to be switched to a selecteddestination address based on a control signal, the control signalprovided for selecting desired video data and for selecting thedestination address; and selecting and outputting the selectedpacketized video data to a destination corresponding to the selecteddestination address on a frame basis, such that if the selecteddestination address is changed when a received packet of video data isnot a predetermined packet in a frame, the switch unit does not outputthe packetized video data to a changed destination until thepredetermined packet is received.
 6. The relay apparatus of claim 5,wherein the packetized video data includes a head packet, and whereinthe selecting and outputting starts from a head packet of a next frameof the selected packetized video data.
 7. The relay apparatus of claim6, wherein each packet of video data includes a marker bit thatidentifies a final packet of a video frame.
 8. The relay apparatus ofclaim 7, further comprising determining the head packet of the nextframe of the selected packetized video data based on the marker bit. 9.A camera system comprising: a plurality of camera apparatuses configuredto output video signals in the form of packetized video data; and arelay apparatus for selecting the packetized video data provided fromthe plurality of camera apparatuses, the relay apparatus comprising: areceiving unit to receive the packetized video data from the pluralityof camera apparatuses; an analyzing unit to determine if selectedpacketized video data from a particular one of the plurality of cameraapparatuses is to be switched to a selected destination address based ona control signal, the control signal provided for selecting desiredvideo data and for selecting the destination address; and a switch unitto select and output the selected packetized video data to a destinationcorresponding to the selected destination address on a frame basis, suchthat if the selected destination address is changed when a receivedpacket of video data is not a predetermined packet in a frame, theswitch unit does not output the packetized video data to a changeddestination until the predetermined packet is received.
 10. The camerasystem of claim 9, wherein the packetized video data includes a headpacket, and wherein the switch unit selects and outputs starting from ahead packet of a next frame of the selected packetized video data. 11.The camera system of claim 10, wherein each packet of video dataincludes a marker bit that identifies a final packet of a video frame.12. The camera system of claim 11, wherein the switch unit determinesthe head packet of the next frame of the selected packetized video databased on the marker bit.